Ok, I've dug out my multimeter, what could possibly go wrong! I'll simply see if I can determine what voltage goes across what point on the switch. On a serious note, can I do damage by putting the multimeter on certain points? For example two positive points or two negative points?
Ok, I've put the multimeter on the switch and found that there's permanently 5v across it. So when the button is pressed, the voltage is cut and this turns the machine on or off. Whether the machine is on or off, the voltage remains other than the momentary press of the button. Not sure what this means for the plan but I'm sure I can't break that voltage by other means without interfering with the original button.
The Wemo Maker can be configured to either on/off or momentary connection. You can set timers using the Wemo app and add additional configuration using IFTTT.
I think I'm going to go ahead and or a Wemo. Just need to work out a means of getting a 5v USB supply inside the machine. I could alternatively power this from outside but would prefer to keep everything as factory looking as possible.